Telephone coupling apparatus



Sept. 11, C W. DANN TELEPHONE COUPLING APPARATUS Filed Feb. 4, 1944crfes (D (Ittomeg Patented Sept. 11, 1945 UNITED STATES PATENT orrlcs2,884.00" TELEPHONE COUPLING APPARATUSQariesW.Dann,0range,N.J.,a-ignorto 'llsolnu A. Edison, Incorporated,West Orange. N. 1., a corporation of New Jersey Application February 4,1944, Serial No. 521,118

7 Claims. (CI. 179-2) This invention relates to apparatus for making anelectrical coupling to a telephone through the box-f the telephoneapparatus. While the invention contemplates coupling to a telephonesystem for the NW of picking up 18ml energy from the system as well asfor feeding signal energy into the system, the invention is morecommonly used as a pick-up to couple, for example, the input of aphonographic recorder or of a loud-speaking system to a telephone, andit is in terms of such pick-up that the invention is herein illustratedand described.

This invention is especially with im proved mounting apparatus forholding and localising a telephone coupling unit with respecttotheboxotatelephonesystem. Themore common form of coupling unit isofthe magnetic typ comprising aeoilwoundonamagnetic core,

.andthiscoilispositionedsothatitwillbemagnetically coupled with theinduction coil oi the telephone apparatus. In pickingup signal energyfrom telephone systems, however, only a smallpementageoftheiluxoitheinductioncoilis available outside the box forcoupling purposes.

and it is therefore highly important that the pickupcoilbecriticallypositionedrelativetotheinduction coil within the box so thatthe maximum possible coupling coefilcient may be obtained between it andthe induction coil.

It is an object of my invention to provide improved apparatus formounting a telephone coupling unit in relation to the box of a telephonesystem.

It is another object to provide an improved mounting apparatus which.will critically locate the coupling unit relative to the induction coilin the telephone box.

It is another object to provide an improved mounting apparatus whereinthe coupling unit is resiliently supported and urged toward thetelephone box.

It is another object to provide a simple frame or housing member for themounting of a telephone coupling unit which is shaped to fit thetelephone box in a predetermined position relative theretosnd which,when in mounted position, has an exterior outline conformingsubstantially to the shape of the telephone box.

It is another object to provide an improved mounting apparatus for atelephone coupling unit which will maintain the coupling unit in directcontact with the telephone box irrespective of tolerance variations inthe dimensions 0! the parts making up the apparatus.

Itistobeunderstoodthatlhereinusethe term "telephone box to mean theconventional box'of a telephone system wherein, among other components,there is housed the telephone induction coil, and that I mean the termto include both wall boxes and boxes mounted in the base portions ofhand combination desk sets.

Particularly, for hand combination desk sets, it is an object of myinvention to provide a mounting apparatus for the coupling unit which isadapted to provide a stable support for the desk set and maintain thecoupling unit in contact with the bottom wall of the desk setirrespective of variations in the height of the foot pads of the set.

Other and allied objects and features of my invention will more fullyappear from the following description and the appended claims.

In the description of my invention reference is had to theaccompanyingdrawing, of which:

Figure l is a perspective view of a hand combination desk set in mountedrelation with a telephone coupling'apparatus according to one embodimentof my'invention;

Figure 2-is a perspective view of the telephone coupling apparatus ofFigure l with the hand combination set removed;

Figure 3 is a vertical sectional view of the telephone couplingapparatus of the foregoing figtion set in mounted position relativethereto;

Figure 4 is a fractional sectional view takenprincipally on the line 4-4of Figure 3;

Figure 5 is a top plan view of the coupling unit per se with aninsulating shield thereof removed;

' Figure 6 is a perspective view of another embodiment of my inventionapplied to one side of a telephone box of the wall type;

Figure 7 is a fractional sectional view of the coupling apparatus ofFigure 6 taken on a line through the axis of the coupling unit; and

Figure 8 is a perspective view of still another embodiment of myinvention applied to another side of a telephone box of the wall type.

By way of illustration, 1 show in the drawing a. coupling unit i of thepick-up variety. Preferably, for this pick-up, I employ one of themagnetic type comprising a coil 2 constructed in accordance with theteachings of the pending application Serial No. 463,798 of Joseph C.Adams (now Patent No. 2,381,097), which application has a commonassignee with the present application, This pick-up coil is of a long,slender, solenoidal type provided on a laminated magnetic core 3 whichhas a large ratio of length to square root of cross sectional area andwhich has pole portions to at the ends of the coil that extendunidirectionally, radially of the coil, to as far as the periphery ofthe coil. When this form of pick-up coil is mounted in close proximitywith a telephone box and properly oriented with respect to the telephoneinduction coil within the box, with the radially extending poles todirected toward the induction coil, the pick-up coil serves as a highlyefilcient device for picking up signal energy from a telephone system.For further details of the construction of the pick-up coil per se,reference may be had to the pending application abovementioned.

The pick-up coil 2 is housed in a metal case 4 com rising a fiat bottomplate 5 having upturned semicircular portions So at the ends, and asemicircular cover 6 having a flange to at one side by which it is heldto the bottom plate by screws 1. The coil is held fixedly within thiscase by lugs 8 turned down from the ends of the cover and by screws 9which secure the poles 2a to the lugs; as so held, the poles Ia are atright angles to the bottom plate 5 and extend away from that plate tothe top of the cover 6. Lead connections to the coil are made by way ofa shielded cable l which may, for example, have connection to atelephone plug II to facilitate connecting the coil to suitableelectrical apparatus, as to the input of an amplifier, not shown. Theshield of the cable I0, the case 4 and the magnetic core 3 are allinterconnected to provide a common and continuous electrostaticshielding for the coil and its leads. In order however that theshielding may not have direct connection with the telephone box, a layerI2 of insulation, such as of fish paper, is applied over the cover 6 andheld in place by screws l3 which fasten to the bottom plate 5, theinsulation layer conforming to the portions a of the bottom plate 8shown in Figure 4.

The coupling unit above described is mounted within a frame or housingmember ll. Preferably, this frame member is provided in the form of ablock and made of a suitable material such as of wood. In the embodimentof my invention shown in Figures 1 through 5, this frame member servesas a base or support onto which a hand combination desk set I! is to beplaced, the frame member itself having foot pads It at the corners sothat it may rest evenly on any flat surface such as the top of a desk ortable. The top surface of the frame member is adapted to receive thehand combination set in one definite position relative thereto, and tothis end recesses 11 are provided in the frame member at the fourcorners thereof to receive the foot pads ll of the hand combination set.The vertical sides of the frame member are substantially flush with thecorresponding sides of the hand combination set and, with the recessingof the frame member as above explained, the frame member appears as asubstantially even downward extension of the lower box portion lid ofthe hand combination set.

At the central portion of the frame member there is a rectangularopening I! extending through the member and having an upper portion ofnarrow width and a lower portion of substantially greater width as shownin Figure 3. The coupling unit is held in the top portion of thisopening, with the axis of the pick-up coil 2 parallel to the top face ofthe frame member and with the poles 3a extending upwardly at rightangles to this face, and the opening is so located and diagonallypositioned with respect to the sides of the frame member that when thehand combination set is mounted on the frame member the pick-up coilwill be favorably oriented for effective coupling with the telephoneinduction coil.

Normally, the level of pick-up of signal energy from a telephone system,when the pick-up is made without direct connection to the telephonesystem and through the telephone box, as is here considered, is so lowas to require substantially the maximum practical gain realizable froman electric amplifier to increase the pick-up to a sufflciently highlevel capable of satisfactorily operating an electrical apparatus suchas a phonographic recorder or loud-speaker. The use of a pick-up coildesigned according to the teachings of the Adams applicationabove-mentioned materially relieves the gain requirements of theamplifler but, additionally, the gain requirements may be relievedmaterially further provided the pick-up unit is held at a very minimumpossible distance from the induction coll-i. e., in direct contact withthe wall portion of the telephone box which is adjacent the inductioncoil. In order that the pick-up coil may be so held in direct contactwith the telephone box within the range of tolerances of the partsmaking up'the telephone coupling apparatus, and for varying heights ofthe yieldable foot pads I. of the hand combination set, without the handcombination set being ever rockably held by the pick-up unit above theframe member I, I provide a downwardly yieldable mounting forresiliently holding the pick-up unit above the level of the top surfaceof the frame member I, but have the yieldability of this mounting soadjusted that it will be overcome by the weight of the hand combinationset on the pick-up unit. This resilient or yieldable mounting comprisessimply an upwardly bowed spring 20 the ends of which are loosely securedby screws 2| to the bottom of the plate 5, and

a base plate 22 onto which the central portion of the spring 20 is heldby screws 21. This base plate extends across the opening II at thebottom and is held to the frame member by screws 24. The screws 23 servealso to hold in place an insulating strip 25 which carries terminals 26to which the leads of the coil 2 and of the cable II connect.

In Figure 6 I show a frame member 28 which is shaped to fit an exteriorside of a wall box 2! and provide a substantially even extension of therespective side walls of that box. This frame member is held to the boxby a strap 20 and by tensioning springs 2| as illustrated in thedrawing. This frame member comprises a thick portion 28a covered by athin panel 2"). The portion 22a has an opening 22 extendingtherethrough. In this opening there is mounted the coupling unit I andits resilient support comprising the spring 2| and base plate 22 asabove described. Thebase plate 22 is inset in the portion 28a andextended across the opening 32, and the panel portion 22b lies flatagainst the portion 28a to cover the base plate. As in my embodimentabove described, the coupling unit is held yieldably in a positionbeyond the face of the frame member 28 that is to lie adjacent the wallbox. Accordingly, when the frame member is placed in mounted positionagainst the box, as shown in Figure 6. the coupling unit will be held indirect contact with the box. Moreover, it will be understood that thepositioning of the coupling unit relative to the frame member 2| is suchthat the coupling unit will be oriented for maximum coupling with theinduction coil contained within the telephone box.

In Figure 8 I show another form of frame member 35 which is adapted tobe placed against a front side of a wall box and again form asubstantially even extension of the box. This frame member is held inposition against the box by a pair of tension springs 31 at the top andbottom of the box of which only the top springs are shown. These springsconnect for example to pins 38 on the frame member and to a hook 39which engages an opening in the base portion of the wall box. It will beunderstood that the coupling unit I may be yieldably mounted within thisframe member in the same way in which it is mounted in the frame member28 and that, when the frame member 35 is mounted on the wall box asshown, the coupling unit will be held in direct contact with the wallbox for maximum coupling coemcient with the induction coil containedwithin the box.

I have herein shown and described my invention in terms of severalpreferred embodiments but it is to be understood that these embodimentsare intended to be illustrative and not necessarily limitative of myinvention, since the same are subject to changes and modificationswithout departure from the scope of my invention, which I endeavor toexpress according to the following claims. In the claims the term "wallof the telephone box is intended to mean any bounding wall of the boxand, in hand combination desk sets, to include the under side of thedesk set.

I claim:

1. In apparatus for association with a telephone box, including apick-up coil for effecting a magnetic coupling with the telephoneinduction coil contained in said box, said pick-up coil having amagnetic core with pole portions extending radially of the coil: thecombination of a housing for said pick-up coil shaped to cooperate witha wall of said box and be thereby localized in relation thereto; andmeans in said housing for holding said pick-up coil adjacent to the saidwall of said box and in position wherein the coil is axially parallel tosaid wall and said pole portions are directed theretoward.

2. In apparatus for association with a telephone desk set, including amagnetic pick-up coil for eilecting a magnetic coupling with thetelephone induction coil contained within the box of said set: thecombination of a base member for supporting said desk set, said basemember having an uneven top surface adapted for receiving and locatingsaid desk set in a predetermined position in relation thereto, said basemember being adapted to serve as a housing for said pickup coil; andpositioning means within said base member for said pick-up coil, saidpositioning means being adapted to locate said pick-up coil in closeproximity with said box and in substantially axially parallel relationto said induction coil to secure an at least substantially maximumcoupling of the pick-up coil with said induction coil.

3. In apparatus for association with a telephone desk set, including amagnetic pick-up unit for effecting a coupling with the telephoneinduction coil contained within the box of said upwardly against thebottom wall of said box and maintain said pick-up unit in contact withsaid box irrespective of variation in the eil'ective height of said footpads.

4. A device for picking up currents from the induction coil contained inthe box of a telephone system, comprising a pick-up coil forelectromagnetic coupling with said induction coil; a housing for saidpick-up coil having a side thereof adapted to seat onto a wall of saidbox and to be held firmly thereagainst under pressure; and a resilientmounting means in said housing for said pick-up coil, said mountingmeans holding the coil in position wherein it projects beyond said sideof the housing when the housing is disassociated from said box, and saidmounting means being relatively flexible whereby it will yield to saidseating pressure of the housing against the box.

5. A device for picking up currents from the induction coil contained inthe box of a telephone system, comprising a pick-up coil forelectromagnetic coupling with said induction coil; a housing for saidpick-up coil having a side thereof adapted to seat onto a wall of saidbox; and a resilient parallel-motion support on said housing for saidpick-up coil, said support holding said pick-up coil beyond said side ofthe housing when the housing is disassociated from said box, and saidsupport yielding to seating pressure of the housing against said box.

6. A device for coupling to a telephone apparatus contained in the boxof a telephone desk set, said desk set being provided with supportingfeet, comprising a coupling means; a housing for said coupling meansadapted to serve as a supporting base for said desk set and on whichsaid desk set will seat; and resilient mounting means securing saidcoupling means to said housing and urging the coupling means upwardlyabove the top face of the housing, said resilient mounting meansyielding to the weight of the desk set whereby upon placing the desk setonto the housing the desk set will seat thereon and said coupling meanswill contact the bottom wall of the desk set irrespective of variationsin the height of said feet.

7. A device adapted to be mounted onto a telephone box and to effect acoupling with apparatus of the telephone system contained in said boxincluding a coupling means; a housing for said coupling means having aside thereof adapted to seat onto a wall of said box; means forattaching said housing to said box including resilient means for holdingthe housing seated on the box under pressure; and a resilient mountingmeans on said housing for said coupling means, said mounting meansholding the coupling means in position wherein it projects beyond saidside of the housing when the housing is detached from said box, and saidresilient mounting means being adapted to yield to the seating pressureprovided by said attaching means.

CHARLES W. DANN.

